planka/server/api/helpers/get-subscriptions-for-card.js

module.exports = {
  inputs: {
    id: {
      type: 'json',
      custom: value => _.isString(value) || _.isArray(value),
      required: true,
    },
    exceptUserId: {
      type: 'json',
      custom: value => _.isString(value) || _.isArray(value),
    },
  },

  async fn(inputs, exits) {
    const criteria = {
      cardId: inputs.id,
    };

    if (!_.isUndefined(inputs.exceptUserId)) {
      criteria.userId = {
        '!=': inputs.exceptUserId,
      };
    }

    const cardSubscriptions = await sails.helpers.getCardSubscriptions(criteria);

    return exits.success(cardSubscriptions);
  },
};